[Zurück]

S Schaden, A. Domínguez-Vidal, B. Lendl:
"On-line reaction monitoring in the liquid phase using two mid-infrared quantum cascade lasers simultaneously";
Applied Spectroscopy, 60 (2006), 5; S. 568 - 571.

Online monitoring of a model reaction was performed by employing two pulsed mid-IR Fabry-Perot quantum cascade lasers (QCL). The emission maxima of the QCLs were located at 1393 and 1080 cm-1. An optical system of parabolic mirrors and a ZnSe beam splitter combined the two laser beams and allowed a transmission cell to be probed with both QCLs simultaneously. The reaction mixt. was pumped continuously through a cell that had an optical path of 48 mm. This dual QCL system allowed fast absorption measurements of the reaction mixt. at two distinct wavenumbers. The reaction under study was the oxidn. of sulfite to sulfate with hydrogen peroxide acting as oxidant. Online measurements of the chem. reaction allowed direct, real-time monitoring of sulfate formation and hydrogen peroxide depletion.